It has previously been proposed to localize the application of chemotherapy agents for the treatment of cancer tumors by the physical association of magnetic materials and chemotherapy agents in protein microspheres, such as human serum albumin, or other microscopic carriers. In this regard, reference is made to Medical World News, Aug. 21, 1978, p. 57; "Magnetic Targeting of Microspheres in Blood Flow", by C. F. Driscoll et al., Microvascular Research 27, 353-369 (1984), and "Experimental Methods in Cancer Therapeutics", by Kenneth J. Widder et al, Jl. of Pharm. Sciences, Vol. 71, No. 4, Apr. 1982 pp. 379-386. Related patents include K. J. Widder U.S. Pat. No. 4,247,406; R. T. Gordon U.S. Pat. No. 4,106,488; G. H. Czerlinski U.S. Pat. No. 4,454,234. The Widder patent relates to the process mentioned above. The Gordon patent relates to the heating of particles which may be magnetic, by high frequency magnetic fields, as a cancer treatment method. The Czerlinski patent involves aggregation and re-suspension of fine particles in solution where the particles include magnetic material having a predetermined Curie point, and the aggregation and re-suspension is accomplished by varying the temperature above and below the Curie point.
With regard to the use of magnetic particles and chemotherapy agents in microspheres for the treatment of cancer, this technique has been successful with tumors which are localized near the surface of the human body. However, for deep seated tumors, it is not practical to provide a magnetic field which is localized deep within the body. More specifically, the magnetic field is provided by permanent magnets or electromagnets which are mounted outside of the body, and therefore provide a magnetic field which extends from the skin to the deep-seated tumor. Accordingly, if the procedure is employed in such cases, many of the carrier microspheres will be held outside of the desired cancerous zone. Further, because the magnetic field strength drops off with distance from the magnet, higher magnetic field strengths, and correspondingly higher concentrations of the chemotherapy agent will be located near the skin, outside of the deep-seated cancerous zone.
A principal object of the present invention is to overcome the limitations as outlined above on the treatment of deep-seated cancerous tumors or the like.